Scale actuator for vacuum printing frame



Feb. 11, 1958 J. D. PADGETT 2,822,736

scALE AcTUAToR FOR VACUUM PRINTING FRAME Filed July 29, 1955 UnitedStates Patent Ci'ice SCALE ACTUATOR FR VACUUM PRINTING FRAME Jay D.Padgett, Dallas, Tex. Application July 29, 1955, Serial No. 525,321 6Claims. (Cl. 95-77) This invention relates to photocomposing machinesand more particularly to devices for aligning and positioning images tobe transferred from a negative to the sensitized plate in step andrepeat printing on vacuum printing frames.

The present invention is used in conjunction with the photocomposingmachine described in U. S. Letters Patent No. 2,713,294, issued to l ayD. Padgett July 19, 1955, wherein scale members and a negative holder offerrous metal are magnetically held in registered relationship with eachother and with the sensitized plate by a magnetic lield underlying therubber make-up mat so that their positions will remain unchanged whilecreating a vacuum in the Vacuum frame to bring the negative and plateinto intimate contact with the glass cover of the frame preliminary toexposing the same to light. It is desirable, to insure againstdistortion, that the work be devoid of any prominences which wouldprevent ush contact of the negative and plate with the glass cover ofthe frame. When the scale members or negative holders or both aremagnetically retained, it is ditlcult to shift the longitudinal scalemember, especially minute distances to insure the necessary precisionadjustment of the negative in relation to the sensitized plate. It isdesirable, therefore, to pro vide detachable means for effectinglongitudinal displacement of at least one of the scale members in suchmanner as to easily control its displacement for precision setting.

It is therefore the principal object of the invention to provide adevice for accurately positioning scale members and negative holders inrelation to each other and to a sensitized plate in a photocomposingmachine.

Another object is to provide a device of the character set forth incombination with the magnetic base for the make-up mat of a vacuumprinting frame.

Briefiy, the invention consists of a c-alibrated longitudinal Hat bar orscale member having teeth formed in its lower edge, whose oppositesmooth edge is abutted by the lower end of a transverse scale memberwhose calibrations determine the placement of a negative holder inrelation thereto and consequently the negative in relation to thesensitized plate on which the negative is superimposed. A retainer platejoins the scale members in their described relationship so that thelongitudinal scale member may be shifted longitudinally by means of apinion insertable through a hole in the retainer plate to engage theteeth of the longitudinal scale member to shift the same longitudinallythrough the medium of a knob attached to the pinion, the latter beingremovable to permit closing of the transparent cover of the printingframe after all adjustments are made.

Other and lesser objects will become manifest as the descriptionproceeds when considered in connection with the annexed drawing therein:y

to the scale bar 22 by means Figure 1 is a top plan view of la vacuumprinting frame with parts broken away to show the magnet bed below thework surface and showing thereon the sensitized plate, negative and thepositioning elements.

Figure 2 is an exploded view in top perspective in which the scalemembers are fragmentarily shown, and

Figure 3 is a fragmentary sectional view taken on line :5*3 of Figure l.

The structure of Figure 1 can be better understood by referring to theabove identified patent. In this iigure, reference numeral 10 denotesgenerally the cabinet of the printing machine in which the printingframe, broadly designated by reference numeral 11, is tiltable from aslightly inclined position to a vertical position for printing on pivotpins 12. A magnet bed, generally indicated by reference numeral 13, issuitably supported in the printing frame 11 and carries a multiplicityof permanent magnets 14 which are arranged in end to end relationship inrows extending diagonally across the bed, as shown, and held for limitedmovement perpendicular to the plane of the bed.

A rubber blanket 15 lies flush against the magnets and it is upon thisblanket that the sensitized plate 16 is placed. The printing frame 11has a cover frame 17 hinged thereto along its rear edge and lockable tothe printing frame at its front corners (not shown). The cover frame hasa gl-ass panel 18 and when closed on the printing frame defines anair-tight compartment in which is drawn a partial vacuum to cause theblanket 15 to be influenced upwardly, pressing the negative 19, in closeunion with the plate 16, firmly against the glass 18. It is thereforenecessary, to insure against wrinkles and shadows that the elements usedto position the negative 19 and plate 16 be as at or thin as possibleand that the means for holding these elements leave no prominences whichwould interfere with ush engagement of the negative and plate with theglass 18.

In preparing the machine for printing, a calibrated rule bar 20,negative holder 21 and a scale bar 22 are employed. These elements mayall be made of ferrous metal, preferably of high grade steel. It may bedesirable that only the negative holder 21 be made of ferrous metal tobe attracted and held by the magnets 14 in adjusted positions.

The initial step of laying out the work may be accomplished on a lighttable or other at surface and transferred to the blanket 15 o'f themachine for alignment on the sensitized printing plate 16. The scalemembers 20 and 22 or at least the negative holder 21 will be stronglyattracted by the magnetic field created by the magnets 14 over which thework is placed for printing.

It is first necessary to position the negative 19 accurately wi-threspect to the scale bar 22 or its equivalent, after which the negativeholder 21, which is simply a thin dat rectangular strip of ferrousmetal, is located with respect of a single line 23 midway of its endsand which is brought into proper register with the calibrations on thescale bar 22. The negative is secured to the negative holder 21 by meansof a strip 24 of adhesive material which is applied to the undersurfaceof the negative and negative holder.

The foregoing relates to elements fully illustrated and described in theforesaid patent. The invention will now be described.

The lower end 25 of the scale bar or transverse scale 22 is made muchwider than the upper portion thereof to afford a wider bearing surfacefor the longitudinal scale bar 20 whose smooth edge 26 slides aaginstthe corre- "negarse 3 sponding smooth lower edge 27 (Figure 2) of thewidened base 25 ofthe scale member 22. The opposite edgev of thelongitudinal scale bar is provided with a coextensive row of teeth 28.

A bearing plate 29 is longitudinally recessed to denne a coextensiveshoulder 3i) and a ledge 31 on which rests a iloating bar 32. This bar32 is made movable laterally in relation to the shoulder 3) by virtue oftransverse, longitudinally spaced slots 33 therein through which extendregistering'studs'34 rising 'from the' ledge 3i of the bearing plate 29and whose height is equal to the thickness of the floating bar 32.interposed. between the shoulder'30 and the confronting edge 35 of the.oating bar 32 is a lengthv of corrugated ilat spring steel 36 whichresists movement of the bar 32 toward the shoulder `Sitter the purposeto Vbe presently explained;

Overlying the bearing plate 29, the iloating'bar 32 and the' scalemember 20 which slides between the edge of Vthe ledgeY 31 and the loweredge 27 of the scale member 22, is a retainer plate 37 which issubstantially square'in shape. Theretainer plate 37 and bearing vplate`29 are secured to" thebase of the magnet bed 13 by screws 438,extending through holes 39 in the retainer plate 37 and holes 40 in thebearing plate 29 and into threaded holes, not shown, in the magnet base.The opposite edge of the retainer plate 37 is secured t'o the widenedlower portion of the scale bar 22 by screws 41 passing through holes 42in the retainer plate and are lthreaded in holes 43 in the widenedportion 25 'ofthe scale member 22.

The retainer plate 37 has a hole 44`therein into which is passed apinion 45, carrying a handle or operating knob 46. Thesfloating bar 32has a recess 47 accommodating Vthe .pinion 45 'in its operative positionin engagement with the teeth 28 of the scale member 2t).

To assemble the described parts, the bearing plate is lirst positionedasshown and the floating bar 32 is placed againstY thespring 36. The scalebar 20 is then placed with its toothed edge against the recessed edge ofthe oating bar 32. The scale bar 22 is then disposed with the edge 27against the smooth edge 26 of the longitudinal scale bar 20, whereuponthe retainer plate 37 is positioned over the longitudinal bar 2t) toregister its holes 39 with the holes 4t) of the bearing or mountingplate 29. The screws 38 are then inserted into the matching holes 39 and40. In order to bring the holes 42 of the retainer plate 37 intoregister with the holes 43 in the widened end 25 of the scale bar r22,the latter must be thrust against the longitudinal scale bar 20 toovercome the resistance of the spring 36 through the floating bar-32,after which the screws 41 are inserted into the now matching holes 42and 43. Resistance of the spring 36 maintains frictional contact of theoating bar 32 with the longitudinal scale bar 2i) and between the latterand the edge V27 of the widened end 25 so that the scale bar 20 will notmove except when urged `in, a longitudinal direction as by rotating thepinion 45 by its knob 45 which insures fineness of adjustment ascompared with etorts to accomplish such adjustment entirely with thehands. Surface friction on the underside of the scale member 2i),especially when the surface is rubber, prevents precise movement of thelongitudinal scale member V2i) except by the means'shown and described.

e When proper adjustment of the scale member 2t) has' been made, thepinion 45 is Vremoved so that no projection -remains above the commonplane of the retaining elements which would prevent flush contact of thework with the, glass 18 when the cover is closed on theprinting frame l.In combination with the make-up mat and transparent cover of aphotocomposing machine, means for posi tioning a negative in relation toa sensitized plate on said make-up mat comprising a negative holder,transverse scale member to which said negative holder is detachablysecured, a longitudinal scale member, means including a retainer platefor holding said longitudinal scale member yieldably and slidablyagainst an end of said transverse scale member and means extendingthrough a hole in said retainer plate and engageable with saidlongitudinal scale member for adjusting the same in a plane at rightangles to the plane of said transverse scale member, said adjustingmeans being removable to permit close union of said make-up mat and saidcover in closed position of the latter.

2. ln combination with the make-'up mat and transparent cover of aphotocomposing machine, means for positioning anegative in relation to asensitized plate on said make-up mat comprising a longtiudinal scalemember and a transverse scale member perpendicular to said longitudinalscale member and to which said negative is attached in overlyingrelation to said sensitized plate, means including a retainer plate forholding said longitudinal scale member in yieldable sliding engagementwith an end of said transverse scale member and means extending throughan aperture in said retainer plate and engaging said longitudinal scalemember for moving the same in a plane at right angles'to the plane ofsaid transverse scale member, said scale member moving means beingremovable to permit ush relationship between said make-up mat and saidcover in closed position of the latter. Y

3. The structure of claim 2 wherein one edge of said longitudinal scalemember is formed with teeth, said removable means comprising a pinionengaging said teeth and Vrotatable to effect longitudinal movement ofsaid longitudinal scale member.

4. In combination with the make-up mat and 'cover of a photocomposingmachine, a means for positioning a negative in relation to a sensitizedplate on said make-up mat comprising a longitudinal scale memberoverlying the lower edge of said sensitized plate, a transverse scalemember perpendicular to said longitudinal scale member to which saidVnegative is attached, means holding said longitudinal scale member todispose one of its edges in .longitudinal sliding engagement with thelower end of ,said transverse scale member and means engaging theopposite edge ofsaid longitudinal scale member for moving the samelongitudinally, `said means comprising a pinion carrying an operatingknob, saidpinion engaging in a row of teeth in andV coextensive with oneedge of said longitudinal scale member, said operating knob beingremovable to permit flush engagement of said make-up mat and said coverin closedposition of the latter.

5. In combination with Vthe make-up mat and transparent cover of aphotocomposing' machine, means for positioning a negative in relation toa sensitized plate on said make-up mat comprising a longitudinal scalemember and a transverse scale -member perpendicular to said longitudinalscale member and to which said negative is attached in overlyingVrelation to said sensitized plate, a

mounting plate recesse'dto define a longitudinally coextensive shoulderand-'a ledge, a spring steel corrugated strip lying againstsaidlseh'ciulder and a floating bar supported'on said ledge-for limitedlateral displacement under the resistanceiofsaidV strip and againstwhich the toothed preparatory to exposing the work to light in the usuali V,prescribed manner.

Manifestly, the construction as shown 'and' described is capable of somemodiiica-tion and such modification as may be construed to fall withinthe scope and meaning of the appended claims is also considered to bewithin the spirit and intent of the invention, y y

VWhatisclaimettis:Y

edge ofsaid longitudinal scale member is adapted to slidably engage andmeans insertable through an aperture insaid retainer plate and engagingsaid longitudinal scale member for moving the'same in a plane atrig'htangles' to V'the' plane ofV said transversescale member.

6. In combination` withY the printing' frameV of a' photofc'o'mposingmachine, a means for positioning a negative in relation-to -a sensitizedplateV on said printingframe c'omprising a longitudinal scale 'memberoverlying the lower edge of said sensitized plate, a transverse scalemember perpendicular to said longitudinal scale member to which saidnegative is attached, means holding said longitudinal scale member todispose one of its edges in longitudinal sliding engagement with thelower end of said transverse scale member, said holding means comprisinga bearing plate having a longitudinal recess defining a longitudinallycoextensive shoulder and ledge, a bar on said ledge movable laterally inrelation to said shoulder and against which References Cited in the leof this patent UNITED STATES PATENTS Huebner Aug. 22, 1933 Padgett July19, 1955

